Organization of the Spinal Cord

Question 1

Cervical enlargement of the spinal cord is due to

Answer 1

innervation of the upper limb

C5-T1

Question 2

Lumbosacral enlargement of the spinal cord is due to

Answer 2

innervation of the lower limb (L2-S3)

Question 3

C1 - C7 spinal nerves emerge

Answer 3

above the corresponding numbered vertebrae

Question 4

C8 spinal nerves emerge between

Answer 4

C7 v and T1 v

Question 5

T1 spinal nerves and below emerge

Answer 5

caudal to the corresponding numbered vertebrae

Question 6

C1 and coccygeal spinal nerves have

Answer 6

ventral root (motor) fibers ONLY

Question 7

Cauda Equina

Answer 7

Consists of dorsal and central roots of the lumbar and sacral spinal nerves

Question 8

Spinal level =

Answer 8

a region of the spinal cord that is between two intervertebral foramen

Question 9

A pair of dorsal and ventral roots (spinal nerve) exit the vertebral column via

Answer 9

corresponding intervertebral foramen

Question 10

Spinal cord of embryo is

Answer 10

same length as vertebral column

Question 11

Vertebral column and dura mater grow at a ____ rate compared to the spinal cord

Answer 11

faster

Question 12

24 week fetus, where is the caudal end of the spinal cord

Answer 12

level S1 vertebrae

Question 13

In newbron, spnal cord ends at

Answer 13

L2 or L3 vertebrae

Question 14

In the adult the spinal cord ends at

Answer 14

the inferior border of L1 vert

Question 15

In the adult, the dura and arachnoid end at

Answer 15

S2 vertebrae

Question 16

The pia forms the

Answer 16

filum terminale which extends and attaches to periosteum of the first coccygeal vert

Question 17

Lumbar puncuture safely performed where

Answer 17

In adult, caudal tip of spianl cord may extend to space btw L2 and L3 vert
So safe puncture in space btw 4 and 5

Question 18

Spinal cord consists of

Answer 18

gray and white matter

Question 19

Gray matter of spinal cord is the

Answer 19

butterfly shape in center
Contains primarily nerve cell bodies and neuroglia
Synaptic contacts occur here
It is arranged into nuclei - collections of nerve cell bodies

Question 20

The gray matter of the spinal cord consists of:

Answer 20

1. Dorsal horn
2. Intermediate zone
3. Lateral horns
4. Ventral horns Laminae of Rexed
5. Distinctive columns of neurons

Question 21

dorsal horns contain

Answer 21

1. Central processes of pseudounipolar neurons whose cell bodies are in the DRG
2. Tract cells whose axons form ascending tracts
3. Axon terminal of descending tracts
4. Interneurons

Question 22

intermediate zone contains

Answer 22

1. interneurons which are local circuitry neurons

Question 23

Lateral horns contain

Answer 23

1. preganglionic sympathetic nerve cell bodies

2. Present at T1-L2/3 spinal cord levels

Question 24

Ventral horns contain

Answer 24

1. motor neurons whose axons innervate skeletal muscle
2. Their medial region contains motor neurons that innervate axial muscles
3. their lateral region contains motor neurons that innervate limb muscles

Question 25

Laminae of Rexed

Answer 25

10 layers of neurons in the spinal cord gray matter, each layer forming a longitudinal column

Question 26

Lamina II

Answer 26

substantia gelatinosa Contains interneurons which play a role in modulation of nociceptive transmission filters the pain that we feel to prevent it all from reaching higher brain centers and entering conciousness

Question 27

Laminae 4, 5, 6

Answer 27

Nucleus proprius | COntains the neurons of the spinothalamic tract

Question 28

Lamina 9

Answer 28

contains motor neurons whose axons run in peripheral nerves to innervat skeletal muscle

Question 29

Intermediolateral cell column

Answer 29

corresponds to lateral horn Column of autonomic neurons in the T and upper L segements of the spinal cord Contains the cell bodies of preganglionic sympathetic neurons

Question 30

Nucleus Dorsalis

Answer 30

Clarkes Column A column of neurons in the T and upper L segments Origin of the dorsal spinocerebellar tract

Question 31

Sacral autonomic nucleus

Answer 31

column of neurons in the mid sacral segments | contains cell bodies of preganglionic parasympathetic neurons

Question 32

White matter

Answer 32

Surrounds gray matter Consists mainly of myelinated axons and neuroglia Tract, Fasiculus, commissure

Question 33

Naming tracts

Answer 33

Tracts that originate in spinal cord and ascend --> Name starts with spino Tracts that arise in higher brain ceters or the brainstem and descend to synapse in the spinal cord --> name ends in spinal

Question 34

White matter consists of

Answer 34

1. Dorsal funiculus 2. Lateral funiculus 3. Ventral funiculus 4. Ventral white commissure 5. Dorsolateral tract

Question 35

Dorsal Funiculus

Answer 35

``` Fasciculus gracilis (medially) Fasciculuc cuneatus (laterally) Relays discriminative touch, vibratory sense, position sens and light touch sensation from the body ```

Question 36

Lateral Funiculus

Answer 36

Lateral corticospinal tract - motor Rubrospinal tract - motor Dorsal spinocerebellar tract - position sense Lateral spinothalamic tract - paint, temp, touch Ventral spinocerebrellar tract - position sense

Question 37

Ventral funiculus

Answer 37

Anterior corticospinal ract - motor

Question 38

Ventral White commissuure

Answer 38

decussating (crossing) axons

Question 39

Dorsolateral Tract

Answer 39

Btw tip of dorsal horn and spinal cord surface Consists of central processes of sensory unipolar neurons relaying pain and temp sensation from the body contains short ascending and short descending fibers

Question 40

Most whte matter is found in the

Answer 40

cervical region and the least in lumbosacral

Question 41

Why more white matter in cervical?

Answer 41

more and more axons joining the ascending tracts and starting at cervical region, descending axons leave the descending tracts to terminate at lower cord levels and therefore deplete the white matter

Question 42

Descending tracts become progressively ___ as they descend

Answer 42

thinner | As mroe and more fibers exit the tract to terminate and synapse

Question 43

Ascending tracts become progressively ___ as they ascend

Answer 43

thicker | as more and more fibers are added to the tract to ascend to the brain

Question 44

General functions of the spinal cord

Answer 44

.1. Receives sensory input from somatic and visceral structures of the body and either prodesses it at the spinal level or relays it to higher centers via ascending tracts 2. Contains cell bodies of motor neurons whose axons innervate skeletal muscle with motor innervation 3. Contains cell bodies of autonomic neurons involved in innervation of smooth, cardian, glands 4. Contains nerons involved in reflex activity 5. Carries axons of long descending motor tracts that influence spinal cord motor neurons that innervate skeletal muscle of UL, trunk, LL

Question 45

complete transection of the cord at upper cervical levels results in

Answer 45

Quadriplegia Loss of sensation below level of lesion (below neck) Loss of motor function below lesion (both arms and legs paralyzed)

Question 46

Complete transection of the cord btw C and LS enlargements

Answer 46

Paraplegia Loss of sensation below level of lesion (loss of both leg sens) Loss of motor fun below level of lesion (both legs paralyzed)

Question 47

Lesion at lower level and all sacral spinal

Answer 47

Damage motor neurons and parasympathetic neurons | bowel, urinary, genital organs impacted